Vivo U20 forgotten pattern issue while erasing all data from recovery menu.

Hi there, So I've forgot my pattern for this handset. I rebooted into recovery menu and deicided to cleat all data (I am ok with data loss). But after hitting clear all data its asking me for damn patern again. So I am stuck. I tried installing software (Networking update software) from recover menu. I connected to wifi and then downloaded and installed it. But same issue. I was planning on using android device manager to erase device remotely. But the pattern lock won't work in that case. I've macbook and I tried installing few apps like droidkit/dr fone etc on mac. Then connected handset via USB to see if I can remove this pattern. But all these tools are paid version. Which I don't want to use. How do I reset my phone now? This is old device and is on android 9. Vivo do have funtouchOS. PS - I have adb installed and dev tools enabled on this handset. But this phone is not rooted.